Call Sign LookUp

On Nov 29th 2015, I had launched a new web service facility to look up HAM Radio License Call Signs details. The service offers a simple, no-nonsense, free service that folks can get to w/o cluttered look and feel. Additionally, the service offers an output format that is easily parse-able, and consumable from other services. Below here you will find some more details about this service facility.

this was primarily due to added lat/lon coordinates discovery logic. Which will be decoupled as an optional param driven request in the future

Caching and Performance

As of Dec 4th 2015 early morning, I had rolled out an update to the facility to take advantage of the RASPI NGINX/PHP server stack’s Caching features. The following features are active:

should make consecutive calls to the page w/ previously looked up call signs much faster.

cache is active for up to 15m of inactivity per call sign

cache is large enough to store up to 2500 calls and then it tumbles over to refresh

server is still running on one RASPI behind the cluster. Soon to be upgraded to multi-RASPIs for redundancy

Load Balancing and Redundancy

As of Dec 5th 2015 early morning, I had rolled out a load balancing frame sitting behind the facility. This should not only provide load balancing capability, but, also provide a good redundancy platform.

Currently, the frame is designed as follows:

The main entry point node to the facility/service is a “broker” RASPI that coordinates the backend “worker” nodes

There are currently 3 worker nodes Node-2 thru Node-4

The load balancing is currently defined using “round-robin” mode using NGINX built in capabilities

The responding service output identifies the node that serviced the request.

The caching memory is server specific.

Meaning, if a call-sign was never processed within the last timeout threshold, the servicing node will do a fresh ‘get’ of details of that call-sign.

Current Limitations (ver 1.0):

this ver 1.0 is for the US market only (primarily due to restrictions on data availability from other regions)

Plans to extend to other regions is always in the play as the data becomes available from regions’ data sources (akin to FCC in other countries)

I am excited to see the following 3rd party HAMs’ services using my service in their backend:

APRS Weather Lookup Service by KI6WJP – Martin Nile uses my service to lookup zip codes of those call signs that currently don’t exist in the APRS-IS database. An example YouTube video of Martin’s weather service can be found here

APRS Call-Sign LookUp Service by KI6WJP – Martin Nile uses my service to lookup call sign details. The following is how to use Martin’s APRS callsign lookup service:

Sendan APRS message addressed to KI6WJP with one of the following message texts:

whois <callsign>

info <callsign>

who-is <callsign>

Project Pictures:

Credits:

First off, thanks to the FCC for offering the data as publicly available source for us for the US Market.

Secondly, I want to thank a *few people* for their help in testing the facility and sharing their invaluable feedback to making this service better. here they go and the list keeps growing (in no particular order):

hi Austin – the farm includes 4 RASPIs. The top most one is the “broker” that first receives all incoming HTTP requests and then it sends the requests over to one of the other 3 RASPIs (“workers”) to process the request. The whole unit works in unison and can be deployed as a singleton standalone unit. Hope that helps. Thanks for asking. I must do a series of videos on this project – it’s long ado.